Nuclear magnetic resonance (NMR) spectroscopy is being used to investigate the chemical conjugation of specific benzo (a) pyrene oxides and other arene oxides to glutathione, enzymatically and non-enzymatically. The regiospecificity and stereospecificity of the reaction will be determined. Mechanistic elaboration of the binding process is important in understanding, preventing, and predicting the mechanism(s) of action of such compounds. A high pressure liquid chromatography (HPLC) system was developed to allow analysis of mixtures of glutathione conjugates and to follow their metabolic degradation through several steps down to mercapturic acids.